I had some that I couldn't get to go away. It would creep up on the walls, glass, rock, etc. And the tank was almost bare.

I bought a couple dozen small snails, some of this, some of that, and threw them in my 29g. It was gone within a week.

I do have a bare bottom tank though with a lot of flow, media basket with chemipure, purigen, and a tunze 9002.

Hope that helps